1. Field of the Invention
The present invention relates generally to trailer hitches for vehicles and, more particularly, to a ball coupling installation for a gooseneck type trailer hitch.
2. Description of the Prior Art
Ball type couplers for trailer hitches are well known in the art and commonly used on pick-up trucks to permit the hauling of trailers. Quite commonly, such couplers are mounted to the rear bumper of the pick-up truck. These bumpers have a more restricted load pulling capacity than the truck frame and for this reason coupling devices mounted in this fashion are disfavored over couplers mounted directly to the truck frame.
Couplers useful for gooseneck type trailer hitches are most favorably attached directly to the pick-up truck frame and positioned in the bed so that the gooseneck portion of the trailer can extend over the bed when coupled to the pick-up. Unfortunately, the ball and associated mounting assembly extending upwardly from the bed interferes with and restricts the loading of materials onto the bed. Various means have been employed to eliminate this problem, including retractable mechanisms for retracting the ball coupler below the bed when not in use. The retractable mechanisms have their own disadvantages, in that they undesirably complicate the coupler design as well as the procedures for mounting the mechanism to the pick-up. A yet further disadvantage with certain of these systems is that they are designed for pick-ups having frames of a particular width only and therefore cannot be mounted on pick-up trucks having different frame widths.
Each of the patents listed below relate generally to the field of trailer hitch devices:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 3,791,674 Berends 3,893,713 Ivy 4,256,324 Hamilton 4,456,994 Taylor 4,540,194 Dane 4,570,966 Giboney et al. 4,657,274 Mann et al. ______________________________________
U.S. Pat. No. 3,791,674 to Berends discloses a retractable type kingpin assembly for mounting in the bed of a vehicle. The kingpin assembly is mounted to the bed of the vehicle by a support plate.
U.S. Pat. No. 3,893,713 to Ivy discloses a coupler for a gooseneck trailer hitch having a ball coupler at its end. The coupler is recessed into the bed of the vehicle and is secured thereto by a bed plate mounted to the frame of the truck by four carriage bolts projecting through holes formed in the bed plate.
U.S. Pat. No. 4,256,324 to Hamilton discloses a retractable ball hitch assembly mounted to the truck frame and positioned within the bed of the truck. The assembly mounts directly to the upper surfaces of the rails of the frame beneath the bed via four mounting holes in the web of the assembly.
U.S. Pat. No. 4,456,994 to Taylor discloses an interchangeable universal trailer hitch assembly which is adjustably secured to the truck via the frame and the bed. The hitch assembly includes tubular support members with sliding sleeves thereon which are apertured to permit adjustment for mounting in trucks having different frame widths. The trailer hitch is removable from the rest of the mounting assembly so that the bed area is unobstructed by the hitch. The design is disadvantaged by the need for a reinforcing bed plate which is mounted on top of the truck bed and the fact that adjustment of the support members and sleeves is limited to two positions.
U.S. Pat. No. 4,540,194 to Dane discloses a retractable ball type hitch which is mounted to the truck frame and positioned within the bed of the truck. The device includes a mounting plate which is apparently mounted within a hole in the bed so as to lie flush with the bed. If the mounting plate is not sized to permit direct mounting to the truck frame, the design requires the use of connecting rods welded between the hitch and the frame to mount the hitch to the truck frame.
U.S. Pat. No. 4,570,966 to Giboney et al. discloses a retractable ball type hitch which is retractably housed in a housing welded or bolted to the underside of the truck bed.
U.S. Pat. No. 4,657,274 to Mann et al. discloses a retractable ball type hitch which includes transverse frame members secured to the truck underneath the bed. Hinged covers secured to the bed cover the hitch when not in use.